A conventional technique for detecting end-to-end packet losses is disclosed in Non-patent Document 1. The technique disposes a capturing section on a path between a terminal A and a terminal B, and the capturing section fully captures packets passing therethrough. The technique involves checking sequence numbers of the packets, and detecting a packet loss when the order of the transmission sequence number is inverted.
Non-patent Document 1: Tomohiko OHGISHI, Akira IDOUE, Toru HASEGAWA, Toshihiko KATO, “Design of Performance Monitor for Collecting Statistical Information at TCP Level from One-directional IP Traffic,” 2000 Proceedings of IEICE, B-7-3